Safety device for gasoline tanks



April 14, 1925. 1,533,309

w. E. DURBOROW SAFETY DEVICE FOR GASOLINE TANKS Filed 00's. 5, 1922 E W E-Uurbaraw Patented Apr. 14, 1925.

PATENT OFFICE.

WILLIAM E. DURBOBOW, OF COLUMBIA, PENNSYLVANIA.

AFETY DEVICE FOR GASOLINE TANKS.

Application led Uctober 5, 1922. Serial- No. 592,550.

To all whom it may concern:

Be it known that I, WILLIAM E. DUR- BoRow, a citizen of the United States residing at Columbia, in the county of ancaster and State of Pennsylvania, have invented certain new and useful Improvements in Safety Devices for Gasoline Tanks, of which the following is a specification, reference being had to the accompanying drawings.

This invention relates to fuel tanks such as are used in connection with internal combustion engines on automobiles, aeroplanes, dirigible balloons and the like, and particularly to means for preventing the contents of the tank from becoming ignited and exploding.

In tanks of this character containing a highly volatile and combustible liquid fuel, the tank is initially more or less completely filled with the liquid fuel and as the liquid fuel is removed from the tank air is allowed to enter the tank, this air being either under atmospheric pressure or under a higher pressure than atmospheric and this air taking the place of the liquid which has been displaced in the ordinary operation of the engine. If by any chance the liquid within the tank should get on tire, the air in the 3o tank will support combustion.

It is the main object of my invention to provide means whereby a non-combustible gas shall be caused to lill that portion of the tank not filled with liquid so that no combustion will be supported and the tank,

therefore, cannot catch on re or explode.

A further object is to provide means for causing non-combustible gas to be forced by atmospheric pressure into the tank to take the place of the liquid displaced therefrom without permitting the entrance of air to the tank.

A still further object is to provide means particularly designed for use with an aeroplane, which therefore is particularly light and simple so that it cannot readily get out of order and wherein if by any chance the tank should be turned upside down the noncombustible gas will be allowed to ow freely to the then uppermost portion of the tank and prevent the discharge of the liquid i therefrom.

Other objects have to do with the details of construction and arrangement of parts as will appear more fully hereinafter.

My invention is illustrated in the accompanying drawings, wherein Figure 1 is a vertical section of a liquid tank with my safety device applied thereto, the bag of the safety device being in section and the pip g being partly broken'away;

Figure 2 is an end elevation of the .construction-shown in Figure 1; l

Referring to these drawings, 10 designates a tank for containing gasoline or other liquid fuel such as used in the internal combustion engines of automobiles and aeroplanes. This tank may be of any ordinary shape or form but is shown as provided with a filling trap, designated 11, and with an outlet pipe 12 leading to the carbureter of the engine and with a clean-out opening 13. The filling trap is closed at its upper end by a cap 14 and liquid is trapped within the U-shaped bend of the filling trap so as to form a seal to prevent any inlet of air from the filling pipe into the tank.

Disposed in suitable relation to the tank, as for instance above the tank, or in any other suitable position is a bag 15 or gas reservoir, which is illustrated asl beine` entirely formed of flexible material suc` as rubberized fabric, balloon cloth or the like, which fabric has been rendered impervious to gas, and this bag is suspended at its upper` end from any suitable structure, illustrated diagrammatically as the beam 16. The lower end of this bag has gas-tight connection to a pipe section 17, in turn connected to a T 18, which in turn is connected to a pipe section 19 which enters a valve casing 20, this valve casing being connected to a pipe section 21 entering the tank 10 and normally discharging gas thereinto.

Disposed within the valve casing 20is a normally open check valve 22 shown as held in its open position by gravity. Connected to the T 18 is a buv-pass 23 formed of a plurality of pipe sections, which by-pass extends below the end of the tankl 10 and extends upward into said tank.

In the operation of this invention, the gas container 15 is filled with some noncombustible gas, as for instance carbondioxide or nitrogen, though I do not wish to be limited to the use of these gases. The

trap 11 prevents the outward passage of this` gas when the tank is being filled. As the tank is filled through the trap 11 whatever gas may be contained Within the upper portion of thc tank 10 is forced upward 1nto the gas bag which, when the tank 1s filled withl gasoline, is filled with the non-combustible gas. The filling cap 14I is then disposed upon the trap to close the same. As the gasoline or other inflammable fuel is drawn from the tank 10, the gas Within the container 15 Will be forced by atmospheric pressure into the upper portion of the container to take the place of the liquid which has been removed therefrom. New if a fire occurs which would tend to ignite the liquid fuel, there will be no air within the fuel tank to assist combustion and as a consequence the fuel Within the tank cannot become ignited. The container 15 will, of course, have a cubic content equal to that of the tank 10 so that as the liquid is Withdrawn from the tank 10 the gas will fill the tank. Inasmuch as the gas bag is of flexible material, the sides will collapse under the pressure of the atmosphere as the liquid is withdrawn from the tank 10 so that the gas will be forced by pressure into the tank 10 and there will be constant pressure upon the surface of the liquid within the tank, permitting this liquid to feed out through the pipe 12.

In aeroplanes, it often occurs that the machine has to fly upside down and in this case the liquid within the tank would be forced back into the gas bag. To prevent this, I have provided the check valve 22. The by-pass 23, however, permits the noncombustible gas to pass from the container 15 into the space above the liquid even though the machine is flying upside down so that under all circumstances of operation the space above the liquid will be filled with inert, non-combustible gas.

In order to prevent the liquid in the tank 10 from passing into the by-pass 23 and then upon an overturning movement of the machine passing into the gas container 15, a second check valve 24 may be provided which will normally prevent any passage of liquid into the by-pass 23, but when the machine is turned upside down will permit the flow of gas into the tank as is obvious.

While I have illustrated a particular embodiment of my invention I do not Wish to be limited thereto, as it is obvious that many changes might be made in the details of construction and arrangements of parts without departing in any way from the spirit of the invention.

I claim 1. The combination with a tank for containing liquid fuel and having an outlet, of means for keeping that portion of the tank not filled with fuel filled with noncombustible gas comprising a gas container located outside of the tank and having a capacity at least equal to the capacity of the tank and formed of flexible material whereby it will be submitted to the pressure of atmospheric air, and a pipe leading from the container into the upper portion of said tank.

2. The combination with a tank for containing liquid fuel having an outlet, of means for keeping that portion of the tank not filled with fuel filled with non-combustible gas under atmospheric pressure comprising a flexible gas bag, a pipe lcading from the bag into the tank, a check valve in said pipe closing toward the gas bag, and a by-pass connected to said pipe above the check valve and communicating with the bottom of the tank.

3. The combination with a tank for containing liquid fuel having an outlet, of means for keeping that portion of the tank not vfilled with fuel filled with non-combustible gas under atmospheric pressure comprising a flexible gas bag, a pipe leading from the bag into the tank, a check valve in said pipe closing toward the gas bag, and a by-pass connected to said pipe above the check valve and communicating with the bottom of the tank, there being a check valve located substantially at the junction between the by-pass and the bottom of the tank.

4. The combination with a tank for containing liquid fuel having an outlet and an inlet formed to provide a trap preventing the inlet of air when fuel is filled into the tank, of means for keeping' that portion of the tank not filled with fuel filled with non-combustible gas comprising a gas container in the form of aJ bag of flexible material disposed normally above the tank and connected at one end to the tank by a pipe connection, the bag being operatively supported in this position, the tank having a draw-off pipe.

In testimonywhereof I hereunto affix my signature.

WILLIAM E. DURBOROW.

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